Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07K—PEPTIDES
  • C07K14/00—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
  • C07K14/435—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans
  • C07K14/475—Growth factors; Growth regulators
  • C07K14/505—Erythropoietin [EPO]
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K47/00—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient
  • A61K47/50—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K38/00—Medicinal preparations containing peptides
  • A61K38/16—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
  • A61K38/17—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans
  • A61K38/18—Growth factors; Growth regulators
  • A61K38/1816—Erythropoietin [EPO]
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K38/00—Medicinal preparations containing peptides
  • A61K38/16—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof
  • A61K38/17—Peptides having more than 20 amino acids; Gastrins; Somatostatins; Melanotropins; Derivatives thereof from animals; from humans
  • A61K38/22—Hormones
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P7/00—Drugs for disorders of the blood or the extracellular fluid
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P7/00—Drugs for disorders of the blood or the extracellular fluid
  • A61P7/06—Antianaemics
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K38/00—Medicinal preparations containing peptides

Definitions

• This invention relates to novel protein conjugates, in particular, to novel pegylated proteins, and their methods of making and use.
• One aspect of the present invention relates to pegylated-erythropoietin having greater clinical efficacy and stability during shipment and storage than current erythropoietin formulations.
• PEG polyethylene glycol
• polyethylene glycol molecules are connected to the protein via a reactive group found on the protein.
• Amino groups such as those on lysine residues or at the N-terminus, are convenient for such attachment.
• PEG can be coupled to active biopharmaceuticals through the hydroxyl groups at the ends of the chain using a variety of chemical methods. For example, covalent attachment of PEG to therapeutic polypeptides such as interleukins (Knauf, M. J. et al., J. Biol. Chem. 1988, 263, 15,064; Tsutsumi, Y. et al., J. Controlled Release 1995, 33, 447), interferons (Kita, Y. et al., Drug Des.
• Such polymers i include mPEG-succinimidyl succinate, mPEG-succinimidyl carbonate, mPEG-imidate, and mPEG-cyanuric chloride.
• site-specific pegylation at the N-terminus, side chain and C-terminus of a potent analog of growth hormone-releasing factor has been performed through solid-phase synthesis (Felix, A. M. et al., Int. J. Peptide Protein Res. 1995, 46, 253).
• Site specific pegylation at the N-terminus has also been performed using aldehyde-activated PEG; however such reactions require long reaction times and are heavily dependent on pH.
• the reaction requires from 18 to 36 hours and is generally specific only at acidic pH, becoming random at neural or higher pH (see e.g., U.S. Patent Nos.: 6,077,939 and 5,985,265, each of which is hereby incorporated by reference in its entirety). This limits the available peptides to those that can withstand prolonged acidic conditions.
• An additional method used involved attaching a peptide to extremities of liposomal surface-grafted PEG chains in a site-specific manner through a reactive aldehyde group at the N-terminus generated by sodium periodate oxidation of N-terminal threonine (Zalipsky, S. et al., Bioconj. Chem. 1995, 6, 705).
• this method is limited to polypeptides with N-terminal serine or threonine residues.
• C-terminus of a polypeptide have also been described (Schwarz, A. et al., Methods Enzymol. 1990, 184, 160; Rose, K. et al., Bioconjugate Chem. 1991, 2, 154; Gaertner, H. F. et al., J. Biol. Chem. 1994, 269, 7224).
• these active groups can be hydrazide, aldehyde, and aromatic-amino groups for subsequent attachment of functional probes to polypeptides.
• Site-specific mutagenesis is a further approach which has been used to prepare polypeptides for site-specific polymer attachment.
• WO 90/12874 describes the site- directed pegylation of proteins modified by the insertion of cysteine residues or the substitution of other residues for cysteine residues.
• This publication also describes the preparation of mPEG-erythropoietin ("mPEG-EPO") by reacting a cysteine-specific mPEG derivative with a recombinantly introduced cysteine residue on EPO.
• mPEG-EPO mPEG-erythropoietin
• interleukin- 2 was pegylated at its glycosylation site after site-directed mutagenesis (Goodson, R. J. et al., Bio/Technology 1990, 8, 343).
• Glycoproteins provide carbohydrates as additional target sites for modification.
• the enzyme peroxidase has been modified with PEG-diamine through its carbohydrate moiety (Urrutiogoity, M. et al., Biocatalysis 1989, 2, 145).
• WO 94/28024 describes the methods for preparing mPEG-EPO through periodate-oxidized carbohydrate. The chemistry involved was hydrazone formation by reacting mPEG-hydrazide with aldehyde groups of the carbohydrate moiety on EPO.
• erythropoietin An exemplary protein that demonstrates the need for improved pegylation methods is erythropoietin.
• Erythropoiesis is the production of red blood cells, which occurs to offset cell destruction. Erythropoiesis is a controlled physiological mechanism that enables sufficient red blood cells to be available for proper tissue oxygenation.
• Naturally occurring human erythropoietin (hEPO) is a polypeptide produced in the kidney and is the humoral plasma factor which stimulates red blood cell production (Carnot, P and Deflandre, C (1906) CR. Acad. Sci.
• EPO has been used in the treatment of anemia in chronic renal failure patients (CRF) (Eschbach, J W, Egri, J C, Downing, M R et al. (1987) NEJM 316: 73-78; Eschbach, J W, Abdulhadi, M H, Browne, J K et al. (1989) Ann. Intern. Med.
• CRF chronic renal failure patients
• Proteins including native EPO and its derivatized and modified forms, are also generally formulated with albumin (HSA or serum), and stored and transported at reduced temperature to help maintain product stability through use.
• HSA serum-containing formulations are undesirable because of the risk of contamination by human infectious agents and the high costs associated with pharmaceutical grade HSA and related bioassays.
• ARANESP® (darbepoietin alfa) is a commercially available EPO derivative.
• ARANESP® is supplied in two formulations with different excipients, one containing polysorbate 80 and another containing albumin (HSA), a derivative of human blood.
• Pegylated proteins e.g., EPO derivatives
• the present invention is based on the surprising discovery of novel forms of mono- and di-pegylated proteins, e.g., erythropoietin ("EPO"), and mixtures thereof.
• EPO erythropoietin
• the formulations of the invention exhibit improved in vivo activity, including improved plasma half-lives and stability, relative to recombinant human EPO and/or other commercially available EPO therapeutics.
• the EPO molecules and compositions of the invention further exhibit prolonged stability in protein-free formulations and/or remain stable under standard storage conditions, i.e., storage at standard temperature, e.g., about 25 0 C.
• the invention relates to a pharmaceutical formulation comprising at least one population of erythropoietin proteins wherein each erythropoietin protein is covalently linked to at least one polyethylene glycol molecule; and a protein free pharmaceutical carrier.
• each erythropoietin protein is covalently linked to one polyethylene glycol molecule.
• each erythropoietin protein is linked to two polyethylene glycol molecules.
• the at least one population of erythropoietin proteins is a first and a second population, wherein the first population of erythropoietin proteins is linked to one polyethylene glycol molecule and the second population is linked to two polyethylene glycol molecules.
• the ratio of the first to the second population can range from less than about 1 to about 100, about 10 to about 90, about 20 to about 80, about 30 to about 70, about 40 to about 60, about 50 to about 50, about 60 to about 40, about 70 to about 30, about 80 to about 20, about 90 to about 10, or about 100 to less than about 1, wherein less than about 1 includes an amount undetectable using standard methods known in the art.
• each erythropoietin protein is covalently linked to at least one polyethylene glycol molecule through a particular lysine residue.
• the invention comprises a composition having at least one erythropoietin molecule covalently linked to at least one polyethylene glycol molecule via the amino terminus of the erythropoietin protein, which covalent linkage is not through an aldehyde linkage.
• the invention comprises a composition having at least one erythropoietin molecule covalently linked to at least one polyethylene glycol molecule through a particular lysine residue, which residue is lysine 116.
• the formulation may be capable of storage for an extended period of time without substantial degradation of erythropoietin in a carrier-protein free formulation.
• the present invention also relates to methods of manufacture and use of novel forms of pegylated proteins, e.g., EPO, in particular, for use in pharmaceutical formulations.
• EPO pegylated protein
• the pegylated protein of the invention is a conjugate, wherein the protein is covalently linked to at least one polyethylene glycol molecule.
• the pegylated protein of the invention is an EPO molecule that is covalently linked to one or two PEG molecules.
• the covalent link is by way of the amino terminus of the protein. In another embodiment of this aspect of the invention, the covalent link is via a lysine residue of the EPO protein, e.g. , lysine 116.
• the pegylated proteins of the invention encompass proteins covalently conjugated to at least one polyethylene glycol molecule. In a specific embodiment, the invention encompasses EPO protein covalently conjugated to one or two polyethylene glycol molecules (i.e., mono- or di-pegylated-EPO, respectively), and/or mixtures thereof. In certain embodiments, the pegylated protein conjugates of the invention encompass mono-pegylated protein.
• the mono-pegylated protein of the invention may be uniform in that for each conjugate, the polyethelyene glycol ("PEG") molecule is covalently attached to the protein via the same amino acid residue.
• the mono-pegylated protein of the invention comprises a plurality of conjugates in that, for each conjugate, the single PEG molecule is conjugated to the EPO protein via a differing amino acid residue or the N-terminus of the protein (i.e., the ⁇ -amino group of the protein), wherein the said amino acid residue is one of the amino acid residues suitable for covalent conjugation to PEG as described herein.
• the pegylated protein conjugates of the invention encompass proteins having multiple sites of pegylation, e.g., di-pegylated proteins.
• the multiple- pegylated proteins of the invention may be uniform in that for each conjugate, the two or more PEG molecules are covalently attached to each protein at the same sites.
• the multiple-pegylated protein of the invention comprises a plurality of conjugates in that, for each conjugate, the two or more PEG molecules are conjugated to the protein at any two or more of the available amino acid residues suitable for covalent conjugation to PEG as described herein and/or the amino terminus of the protein.
• EPO conjugates of the invention comprise a plurality of mono- and di- pegylated EPO, wherein the site(s) of the conjugation between the EPO protein and the PEG molecule(s) is(are) non-uniform.
• the methods of production presented herein produce a composition that encompasses a plurality of EPO conjugates, each conjugate comprising an EPO protein covalently linked to one or two PEG molecules, wherein the plurality comprises a conjugate having at least one of said one or two covalent linkages at the amino terminus of the protein, which covalent linkage at said amino terminus in not through an aldehyde linkage.
• the invention encompasses a plurality of EPO conjugates, each conjugate comprising an EPO protein covalently linked to one or two PEG molecules, wherein the plurality comprises a conjugate having at least one of said one or two covalent linkages at the amino terminus of the protein, which covalent linkage at said amino terminus in not through an aldehyde linkage , and one or more of or all of: a conjugate having at least one of said one or two covalent linkages at lysine 116, a conjugate having at least one of said one or two covalent linkages at lysine 52 of the EPO protein, and/or a conjugate having at least one of said one or two covalent linkages at lysine 154 of the EPO protein.
• the invention encompasses a plurality of EPO conjugates, each conjugate comprising an EPO protein covalently linked to one or two PEG molecules, wherein the plurality comprises a conjugate having at least one of said one or two covalent linkages at the amino terminus of the protein, which covalent linkage at said amino terminus in not through an aldehyde linkage , and a conjugate having said one or two covalent linkages at any site suitable for such linkage as described herein or known in the art.
• the invention encompasses a plurality of EPO conjugates, each conjugate comprising an EPO protein covalently linked to one or two PEG molecules, wherein the plurality comprises a conjugate having at least one of said one or two covalent linkages at lysine 116.
• the invention encompasses a plurality of EPO conjugates, each conjugate comprising an EPO protein covalently linked to one or two PEG molecules, wherein the plurality comprises a conjugate having at least one of said one or two covalent linkages at lysine 116, and one or more of or all of: a conjugate having at least one of said one or two covalent linkages at the amino terminus of the protein, which covalent linkage at said amino terminus in not through an aldehyde linkage, a conjugate having at least one of said one or two covalent linkages at lysine 52 of the EPO protein, a conjugate having at least one of said one or two covalent linkages at lysine 154 of the EPO protein.
• the invention encompasses a plurality of EPO conjugates, each conjugate comprising an EPO protein covalently linked to one or two PEG molecules, wherein the plurality comprises a conjugate having at least one of said one or two covalent linkages at lysine 116 and a conjugate having said one or two covalent linkages at any site suitable for such linkage as described herein or known in the art.
• the invention encompasses a plurality of EPO conjugates, each conjugate comprising an EPO protein covalently linked to one or two PEG molecules, wherein said plurality comprises a mono-pegylated EPO having the PEG molecule covalently attached to the EPO protein via lysine 116.
• the invention encompasses a plurality of EPO conjugates, each conjugate comprising an EPO protein covalently linked to one or two PEG molecules, wherein said plurality comprises a mono-pegylated EPO having the PEG molecule covalently attached to the EPO protein via lysine 116 and one or more of or all of: a conjugate having at least one of said one or two covalent linkages at the amino terminus of the EPO protein, which covalent linkage at said amino terminus in not through an aldehyde linkage, a conjugate having at least one of said one or two covalent linkages at lysine 52 of the EPO protein, and a conjugate having at least one of said one or two covalent linkages at lysine 154 of the EPO protein.
• the invention encompasses a plurality of EPO conjugates, each conjugate comprising an EPO protein covalently linked to one or two PEG molecules, wherein said plurality comprises a mono-pegylated EPO having the PEG molecule covalently attached to the EPO protein via the amino terminus of the protein, which covalent linkage at said amino terminus in not through an aldehyde linkage.
• the invention encompasses a plurality of EPO conjugates, each conjugate comprising an EPO protein covalently linked to one or two PEG molecules, wherein said plurality comprises a mono-pegylated EPO having the PEG molecule covalently attached to the EPO protein via the amino terminus of the protein, which covalent linkage at said amino terminus in not through an aldehyde linkage, and one or more of or all of: a conjugate having at least one of said one or two covalent linkages at lysine 116 of the EPO protein, a conjugate having at least one of said one or two covalent linkages at lysine 52 of the EPO protein, and a conjugate having at least one of said one or two covalent linkages at lysine 154 of the EPO protein.
• the invention encompasses any of the foregoing plurality of EPO conjugates, further comprising a conjugate having said one or two covalent linkages at any site suitable for such linkage as described herein
• the plurality of protein conjugates of the invention comprises at least one population of conjugates, wherein said at least one population comprises protein covalently linked to at least one PEG molecule.
• the at least one population of protein conjugates is a first and a second population, wherein said first population is linked to one PEG molecule and the second population is linked to two or more PEG molecules.
• said covalent linkages include non- aldehyde linkages at the amino-terminus of the protein.
• the at least one population of protein conjugates is an at least one population of EPO-conjugates that is a first and a second population, wherein said first population is EPO-PEG covalently linked to one PEG molecule and the second population of EPO-PEG is EPO protein covalently linked to two PEG molecules.
• the ratio of the first population to the second population can range from less than about 1 to about 100, about 10 to about 90, about 20 to about 80, about 30 to about 70, about 40 to about 60, about 50 to about 50, about 60 to about 40, about 70 to about 30, about 80 to about 20, about 90 to about 10, or about 100 to less than about 1, wherein less than about 1 includes an amount undetectable using standard methods known in the art.
• the invention further encompasses a plurality of protein conjugates, each conjugate comprising an EPO protein covalently linked to at least one PEG molecule, wherein administration of said plurality to a subject results in a serum concentration of said plurality, or a serum concentration of one or more components of said plurality, of at least about 10% -700% greater than that obtainable by administration of an equivalent amount (e.g. based on protein concentration or activity units, e.g., EPO units) of a control formulation at about 24, 36 or 48 hours after injection.
• an equivalent amount e.g. based on protein concentration or activity units, e.g., EPO units
• control formulations may be, e.g., recombinant human EPO (rhuEPO), native EPO or a commercial EPO formulation, e.g., ARANESP® (darbopoietin alfa)).
• administration e.g., subcutaneously, intravenously
• administration of the plurality of EPO conjugates of the invention into Sprague-Dawley rats results in a serum concentration of about at least 5% to 700% greater than that obtainable by administration of a control EPO formulation at about 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 68 or 72 hours post administration.
• the invention encompasses any method of administration described herein and/or known in the art suitable for delivery of a therapeutic protein, e.g., a therapeutic pegylated protein, to a subject; such methods include, but are not limited to, intramuscular, parenteral, pulmonary, nasal and oral.
• a therapeutic protein e.g., a therapeutic pegylated protein
• the plurality of protein conjugates of the invention may also include various additional materials, including, in particular, any suitable pharmaceutically acceptable carrier described herein and/or known in the art for administration to a subject.
• the invention encompasses a plurality of
• EPO conjugates each conjugate comprising an EPO protein covalently linked to one or two PEG molecules, wherein administration of said plurality to a subject results in an about at least 5%-250% greater increase in hematocrit that that obtainable by administration of an equivalent amount (e.g., based on EPO units) of a control EPO formulation (e.g., recombinant human EPO (rhuEPO), native EPO or a commercial EPO formulation, e.g., ARANESP® (darbopoietin alfa)) at about 5, 7, 10, 12, 14, 16, 18 or 21 days post administration.
• a control EPO formulation e.g., recombinant human EPO (rhuEPO), native EPO or a commercial EPO formulation, e.g., ARANESP® (darbopoietin alfa)
• ARANESP® darbopoietin alfa
• administration e.g., subcutaneously
• administration of the plurality of EPO conjugates of the invention to Sprague-Dawley rats results in an about 5% greater to about 250% increase in hematocrit that that obtainable by administration of an equivalent amount (e.g., based on EPO units) of a control EPO formulation (e.g., recombinant human EPO (rhuEPO), native EPO or a commercial EPO formulation, e.g., ARANESP® (darbopoietin alfa)) at about 5, 7, 10, 12, 14, 16, 18 or 21 days post administration.
• a control EPO formulation e.g., recombinant human EPO (rhuEPO), native EPO or a commercial EPO formulation, e.g., ARANESP® (darbopoietin alfa)
• ARANESP® darbopoietin alfa
• the invention further encompasses pharmaceutical formulations comprising a plurality of the protein conjugates described herein, and/or comprising one or more of the components of said plurality (e.g., a population of EPO conjugates covalently linked to one PEG molecule and/or a population of EPO conjugates covalently linked to two PEG molecules and/or a population of EPO conjugates covalently linked to one or two PEG molecules, wherein at least one of said one or two covalent linkages is at the amino terminus of the protein, which covalent linkage at said amino terminus in not through an aldehyde linkage), and a protein-free (e.g., serum-free, albumin-free, human serum albumin-free ("hsa-free”)) pharmaceutically acceptable carrier, hi certain embodiments, the pharmaceutical formulations of the invention comprising a protein-free pharmaceutically acceptable carrier may be stored for extended period of time without substantial and/or detectable degradation of erythropoietin as determined by methods described herein and/or
• the pharmaceutical formulations of the invention are stable (i.e., do not exhibit detectable and/or do not exhibit substantial degradation) in such protein-free formulations as determined at least 15 months after storage at about -20 0 C or 4 0 C. In other embodiments, the pharmaceutical formulations of the invention are stable (i.e., do not exhibit detectable and/or do not exhibit substantial degradation) in such protein- free formulations as determined at least 10 months after storage at about 25 0 C or about 37 0 C.
• the stability of pharmaceutical formulations of the invention may be assessed by any method known in the art and/or described herein.
• the stability of the pharmaceutical formulations of the invention is assessed by monitoring alteration in the protein concentration over time as determined by a bicinchoninic acid ("BCA") protein assay.
• BCA bicinchoninic acid
• the stability of the pharmaceutical formulations of the invention is assessed by indication of protein degradation (i.e., EPO conjugate degradation) over time as determined by SDS PAGE analysis.
• the stability of the pharmaceutical formulations of the invention is assessed by monitoring the activity of said formulation over time, wherein said activity is determined by any in vitro or in vivo method known in the art for determination of activity of said formulation (e.g., an EPO formulation).
• the activity of a pharmaceutical formulation of the invention comprising a plurality of EPO-conjugates is evaluated by the ability of said pharmaceutical formulation to induce stem cell differentiation into erythroid cells in vitro.
• Another aspect of the invention relates to a protein conjugate made by the method comprising, reacting a protein with an activated water-soluble polymer in a reaction buffer to covalently link the protein with the activated water-soluble polymer and removing substantially all unlinked water-soluble polymer to obtain said EPO conjugate.
• the activated water-soluble polymer is SC- PEG.
• the activated water-soluble polymer is NHS-PEG.
• the reaction buffer does not comprise aldehyde-PEG and/or the activated water-soluble polymer is not aldehyde-PEG.
• the reaction buffer has a pH of about 6.5 to about 8.5.
• the reaction buffer has a pH of about 6.5 to about 7.5, about 6.6 to about 7.3, or about 6.7 to about 7.1. In preferred embodiments, the reaction buffer has a neutral pH of about 7.0. In certain embodiments, the reaction buffer may further comprise 5%-80% DMSO (v/v), and preferably comprises 10%- 40% DMSO (v/v).
• the methods of the invention may allow lower amounts, i.e., lower concentrations, of PEG to be used in the reaction buffer relative to standard methods known in the art while improving or maintaining similar pegylation efficiencies (i.e., evaluated as amount of pegylated product relative to non-pegylated product) of said known methods.
• the methods of the invention may also allow the use of a reaction at a higher pH than other methods known in the art (e.g., pegylation of a protein using aldehyde PEG (see, e.g., U.S. Patent Nos. 6,077,939 and 5,985,265, each of which is hereby incorporated by reference in its entirety).
• a reaction buffer comprises a molar ratio of protein to activated water-soluble polymer of about 1 to about 3 to about 1 to about 60.
• the reaction buffer comprises a molar ratio of protein to activated water- soluble polymer of about 1 to about 4, about 1 to about 5, about 1 to about 6, about 1 to about 7, about 1 to about 8, about 1 to about 9, about 1 to about 10, about 1 to about 15, about 1 to about 20, about 1 to about 25, about 1 to about 30, about 1 to about 35, about 1 to about 40, about 1 to about 45, about 1 to about 50, about 1 to about 55, about 1 to about 60.
• the reaction buffer comprises a molar ratio of protein to activated water-soluble polymer of about 1 to about 7.
• the removing of substantially all unreacted water-soluble polymer can be accomplished routinely by methods known in the art ⁇ e.g., dialysis, chromatography).
• compositions in particular pharmaceutical compositions, comprising the plurality of EPO conjugates of the invention, or one or more components of said plurality, at therapeutically effective concentrations for increasing the red blood cell production in a subject in need thereof.
• pharmaceutical compositions of the invention are administered to treat or manage a disease or disorder associated with aberrant or deficient red blood cell production, or to alleviate the symptoms thereof, in said subject.
• the subject to be treated has not been diagnosed with a disease or disorder associated with aberrant or deficient red blood cell production, but is determined to have a predisposition for developing said disease or disorder. In still other embodiments, the subject to be treated has not been diagnosed with a disease or disorder associated with aberrant or deficient red blood cell production, but is evaluated by standards of the art as obtaining benefit from said treatment. In certain embodiments, the patient receives a dose at least about once a week. In other embodiments, the patient receives a dose at least about once every two weeks, at least about once every three weeks, or at least about once every month.
• FIG. 1 Amino acid sequence of the predominant, fully processed human erythropoietin (“hEPO”) (SEQ ID NO: 1).
• FIG. 2 Amino acid sequence of erythropoietin, with terminal Arg residue
• FIG. 3A-B (SEQ ID NO:2) [0036] FIG. 3A-B.
• FIG. 3 A Lane 1 is molecular weight marker. Lane 2 is the sample after 5 months of storage at 4 0 C in the formulation buffer. Lane 3 is the control of the sample stored in frozen state at -2O 0 C for 5 months, and lane 4 is the unmodified EPO.
• FIG. 3B Starting from the left side: Lane 1: Sample immediately after production. Lane 2:
• FIGS. 4A-B A: Exemplary tryptic digestion of native EPO.
• B Exemplary tryptic digestion of EPO conjugate prepared according to the Example 1.
• FIG. 5 SDS-PAGE analysis of EPEG conjugates stored at high temperatures for various period of time.
• Lane 1 molecular weight standard in kD (200,
• FIG. 6 Comparison of standard (EPREX® (epoetin alfa)) and EPO conjugate ('EPEG') activity on Erythroid Progenitor Proliferation in MethCultTM -4230 (no
• FIG. 7 Pharmacokinetics Profiles of EPO, EPEG and ARANESP®
• FIG. 8 Comparison of the in vivo activity of EPO conjugates of the invention. The hematocrit level over time of three PEG-EPO samples was compared with that of the native EPO at 5 ⁇ g/rat dosage.
• Y501P EPO modified by branched chain NHS-
• PEG (20,000 KD) having 2PEG-EPO.
• Y5012 EPO modified by branched chain NHS-
• PEG (20,000 KD) having equal amounts of IPEG-EPO and 2PEG-EPO.
• FIG. 9 Time course plot of comparison of 3 different EPEGs (L33, Y5012 and X6012) and native EPO for activity in induction of hematocrit increase in rats.
• FIG. 10 Time course of hematocrit increase in male Sprague-Dawley rats following bolus injection of EPEG or rhu-EPO (2.5 ⁇ g or 5 ⁇ g per animal) or vehicle (PBS)
• FIG. 11 Time course of hematocrit increase in male Sprague-Dawley rats following one or two ("uninjected” or “injected,” respectively) bolus injections of EPEG, rhu-EPO (2.5 ⁇ g or 5 ⁇ g per animal) or vehicle (PBS). The second administration of EPEG or control occurred 14 days post first administration.
• polypeptide conjugates e.g., EPO- conjugates
• an added benefit of such conjugated polypeptides is that less protein (as compared with the wild type or native polypeptide) can be administered, including on a less frequent basis, to achieve the desired therapeutic effect. This, in turn, results in lower raw material costs and incidence of side effects since the amount of protein per dose is substantially reduced.
• the invention relates to erythropoietin conjugated to water-soluble polymers.
• the invention relates to polypeptides conjugated to polyethylene glycol (PEG).
• the EPO conjugates of the invention i.e., EPEG
• the conjugates of this invention have the same uses as EPO.
• the conjugates of this invention are useful to increase the red blood cell productions in a subject in need thereof by stimulating the division and differentiation of committed erythroid progenitors in the bone marrow in the same manner that EPO is used to treat the same or similar subjects.
• the inventors have surprisingly found that the conjugates of the invention require no human serum albumin (HSA) in their formulation for stability during storage.
• the formulations of the invention have the advantage of prolonged stability, lower cost and simplified manufacturing, shipping, storage and quality control relative to currently available EPO- based therapeutics.
• N-terminus As used herein, the term "N-terminus, " "amino-terminus,” or analogous terms when used in the context of a covalent linkage of a protein to another molecule refer to a covalent linkage via the amino-terminal ⁇ -amino group of the protein.
• wild type or “native” refers to a protein or polypeptide in its operative or functional form, preferably as it is found naturally functioning in the body. These terms also refer to the protein in a form in which it has not been artificially modified or altered. The terms can thus relate to recombinant proteins. Accordingly, the terms can refer to a protein with an altered glycosylation pattern, including lack of glycosylation, relative to that as produced in the animal from which the nucleic acid and/or amino acid sequence of the protein was originally derived.
• the "natural function" of a polypeptide means its function prior to covalent modification with a water-soluble polymer. Natural functions include, for example, enzymatic activity, receptor binding (e.g., antibodies), ligand binding, and immunogenicity.
• natural function of erythropoietin refers to the in vivo biological activity of causing bone marrow cells to increase production of reticulocytes and red blood cells.
• erythropoietin or "EPO” refers to a glycoprotein, having the amino acid sequence set out in SEQ ID NO: 1 (FIG. 1) or SEQ ID NO: 2 (FIG.
• EPO refers to both the naturally occurring or recombinant protein, preferably human, as obtained from any conventional source such as tissues, protein synthesis, cell culture with natural or recombinant cells.
• Polypeptides substantially homologous to EPO are functional equivalents which include polypeptides with amino acid sequences substantially the same as the amino acid sequence of SEQ ID NO: 1 (FIG. 1) or SEQ ID NO: 2 (FIG. 2).
• "Substantially the same" in reference to an amino acid sequence is defined herein as a sequence with at least 70%, preferably at least about 80%, and more preferably at least about 90% homology to another amino acid sequence, as determined by the FASTA search method in accordance with Pearson and Lipman, Proc. Natl. Acad. Sci. USA 85, 2444-2448 (1988).
• EPO homologs exhibit equivalent or greater activity as compared to that of native or wild- type EPO as assessed by methods described herein and/or standard methods known in the art.
• EPO Any protein having the activity of EPO, such as muteins or otherwise modified proteins, is also encompassed.
• Recombinant EPO may be prepared via expression in CHO, BHK, COS, HeLa or PER.C6 cell lines or other appropriate cell lines of animal or human origin, by recombinant DNA technology or by endogenous gene activation. Expression of proteins, including EPO, by endogenous gene activation is well known in the art and is disclosed, for example in U.S. Pat. Nos. 5,733,761, 5,641,670, 5,733,746, 5,994,122, 5,733,761, 5,641,670, 5,981,214 and 5,272,071, and international patent publication WO 90/11354 (the contents of each are incorporated herein by reference).
• Erythropoietin for therapeutic uses may be produced by recombinant means (EP-B 0 148 605, EP-B 0 209 539 and Egrie, J. C, Strickland, T. W., Lane, J. et al. (1986) Immunobiol. 72: 213-224), the contents of each of the aforementioned references are incorporated herein by reference.
• the preferred EPO species for the preparation of erythropoietin glycoprotein products are human EPO species. More preferably, the EPO species is the human EPO having the amino acid sequence set out in SEQ ID NO: 1 (FIG.l) or SEQ ID N0:2 (FIG. 2), and most preferably the amino acid sequence set out in SEQ ID NO: 1 (FIG. 1).
• EP-A 0 267 678 (hereby incorporated by reference in its entirety) an ion exchange chromatography on S-Sepharose, a preparative reverse phase HPLC on a C 8 column and a gel filtration chromatography are described for the purification of EPO produced in protein-free culture after dialysis.
• the gel filtration chromatography step can be replaced by ion exchange chromatography on S-Sepharose fast flow. It is also proposed that a dye chromatography on a Blue Trisacryl column be carried out before the ion exchange chromatography.
• conjugates in reference to a protein or polypeptide is a protein or polypeptide or population thereof, that functions in interaction with one or more other chemical groups attached by covalent bonds.
• the protein is erythropoietin or a homolog thereof and the chemical group is a water soluble polymer.
• the protein is erythropoietin or a homolog thereof and the water-soluble polymer is PEG.
• the conjugates of the invention have at least one or two PEG molecules linked to each EPO protein. Even more preferably, the conjugates of the invention are made according to the methods disclosed herein.
• the pegylated proteins of the invention preferably made according to the methods described herein, are generally referred to as "protein conjugates.”
• protein conjugates In a specific example where the protein is erythropoietin ("EPO"), the molecules of the invention are referred to as "EPO conjugates,” “EPEG conjugates,” and/or analogous terms, which terms are used interchangeably.
• EPO conjugates erythropoietin
• EPEG conjugates and/or analogous terms, which terms are used interchangeably.
• protein conjugate and/or “protein conjugates” of the invention also refer to a mixture of inventive conjugated proteins, i.e., a plurality of the inventive conjugated protein, e.g., EPO.
• EPEG conjugate and/or EPO conjugate may refer to a substantially homogenous populations EPO proteins with each EPO protein therein linked with one ("IPEG-EPO;" mono-pegylated EPO) or two ("2PEG- EPO;" di-pegylated EPO) PEG molecules, and or combinations of the foregoing.
• Most polypeptides have a plurality of potential PEG linkage sites. Therefore, although a homogenous population of IPEG-protein conjugates has one PEG molecule linked to each protein molecule, that linkage may not necessarily be in the same location on each protein in the population.
• the invention encompasses a plurality of EPO conjugates, each conjugate comprising an EPO protein covalently linked to one or two PEG molecules, wherein said plurality comprises an EPO conjugate having at least one of said one or two covalent linkages to PEG molecules(s) via lysine 116.
• the invention encompasses a plurality of EPO conjugates, each conjugate comprising an EPO protein covalently linked to one or two PEG molecules, wherein said plurality comprises an EPO conjugate having at least one of said one or two covalent linkages to PEG molecules(s) via the amino terminus of the EPO protein, which covalent linkage at said amino terminus in not through an aldehyde linkage.
• the invention encompasses a plurality of EPO conjugates, each conjugate comprising an EPO protein covalently linked to one or two PEG molecules, wherein said plurality comprises an EPO conjugate having at least one of said one or two covalent linkages to PEG molecules(s) lysine 52, or lysine 154.
• the invention encompasses any of the foregoing plurality of EPO conjugates and a conjugate covalently linked to said one or two PEG molecules via any site known in the art to be suitable for such linkage.
• the plurality of protein conjugates ⁇ e.g., the heterogeneous mixture of EPEG conjugates) comprising IPEG-protein and 2PEG-protein conjugates refers to a mixture of the two aforementioned populations, wherein each population may or may not be homogenous.
• the ratio of the mixture of IPEG-protein conjugate to 2PEG-protein conjugate is less than about 1 to about 100, about 10 to about 90, about 20 to about 80, about 30 to about 70, about 40 to about 60, about 50 to about 50, about 60 to about 40, about 70 to about 30, about 80 to about 20, about 90 to about 10, or about 100 to less than about 1, wherein less than about 1 includes an amount undetectable using standard methods known in the art.
• the "water-soluble polymers" encompassed by instant invention include, but are not limited to, polyalkylene glycol and derivatives thereof, including PEG, methoxylated PEG (“mPEG”), PEG homopolymers, polypropylene glycol homopolymers, copolymers of ethylene glycol with propylene glycol, wherein said homopolymers and copolymers are unsubstituted or substituted at one end with an alkyl group.
• the polymer is mPEG and most preferably mono-methoxylated PEG.
• the water soluble polymers can be linear, branched, or star-shaped with a wide range of molecular weights.
• the size of the PEG can range from 10 to about 100 kD. In specific embodiments, the size of the PEG is about 10 to about 40 kD.
• activation methoxylated PEG
• mPEG methoxylated PEG
• mPEG can be activated for subsequent covalent attachment to amino groups by methods well known in the art, i.e., mPEG can be modified to contain varying reactive moieties suitable for subsequent attachment to proteins via amino acid residues containing available amino residues, e.g., lysinyl residues.
• Such activated mPEG polymers include mPEG-succinimidyl succinate, mPEG-succinimidyl carbonate, mPEG-imidate, and mPEG-cyanuric chloride.
• mPEG-succinimidyl succinate methoxy polyethylene glycolyl succinimidyl succinate
• SS-PEG methoxy polyethylene glycolyl succinimidyl succinate
• PEG can be activated by any method known in the art and/or described herein.
• N-hydroxy-succinimidyl-PEG is used as the activated PEG.
• poly(ethylene glycol)-succinimidyl carbonate (“SC-PEG”) is used as the activated PEG (see, e.g., U.S. Patent No. 5,122,614, which is incorporated by reference in its entirety).
• SC-PEG poly(ethylene glycol)-succinimidyl carbonate
• the reaction for covalent attachment of SC-PEG to a protein results in the release of an N-hydroxysuccinidyl group and a PEG- chain attached to the polypeptide through a carbamate linkage via an amino group of the protein (see, e.g., U.S. Patent No. 5,122,614).
• the conjugation reaction may be controlled such that the site of pegylation may be preferentially selected (e.g., preferential selection between an amino-terminal ⁇ -amino group and an ⁇ -amino group of a lysinyl residue).
• the invention encompasses methods of activating
• PEG chloroformate is generated in situ by treatment of the polymer (PEG) with phosgene.
• the resulting chloroformate is then reacted with N-hydroxysuccinimide (HOSu) followed by triethylamine (TEA) to yield the desired activated derivatives of PEG.
• the activated polymer preparations may then be purified from the low molecular weight reactants and evaluated for the presence of the theoretical amounts of active groups.
• any protein may be pegylated according to the methods described herein, the invention, in particular, encompasses the pegylation of therapeutic polypeptides.
• the therapeutic protein for use in accordance with the methods of the invention may be, e.g., a protease, pituitary hormone protease inhibitor, poietin, colony stimulating factor, hormone, clotting factor, anti-clotting factor, neurotropic factor, rheumatoid factor, CD protein, osteoinductive factor, interleukin, growth factor, interferon, cytokine, somatomedian, chemokine, immunoglobulin, gonadotrophin, interleukin, chemotactin, interferon, lipid-binding protein allergen, or a combination of the foregoing.
• a protease pituitary hormone protease inhibitor, poietin, colony stimulating factor, hormone, clotting factor, anti-clotting factor, neurotropic factor, rheumatoid factor, CD protein, osteoinductive factor, interleukin, growth factor, interferon, cytokine, somatomedian, chemokine, immunoglob
• Such therapeutic proteins include, interferon- ⁇ 2A, interferon- ⁇ 2B, interferon ⁇ , interferon- ⁇ , insulin-like growth factor- 1 (IGF-I), insulin-like growth factor-2 (IGF-2), insulin, human growth hormone (hGH), transforming growth factor (TGF), erythropoietin (EPO), ciliary neurite transforming factor (CNTF), thrombopoietin (TPO), brain-derived neurite factor (BDNF), IL-I, insulintropin, IL-2, glial- derived neurite factor (GDNF), IL-I RA, tissue plasminogen activator (tPA), superoxide dismutase (SOD), urokinase, catalase, streptokinase, fibroblast growth factor (FGF), hemoglobin, neurite growth factor, adenosine deamidase (NGF), granulocyte macrophage colony stimulating factor (GM-CSF), bovine growth factor
• the preferred conjugates are made by reacting native protein or polypeptide with an activated water-soluble polymer.
• the water-soluble polymer is PEG.
• the water-soluble PEG is mPEG.
• the mPEG has a molecular weight of about 10 to about 100 kD, more preferably, about 10 kD to about 50 kD, even more preferably about 10 kD to about 25 kD and most preferably, about 12 kD.
• the activated PEG is N-hydroxy-succinymide-PEG ("NHS-PEG”).
• the activated PEG is a succinimidyl carbonate ester ("SC-PEG").
• the activated PEG and the native EPO react in a reaction buffer.
• Variant EPEG i.e., EPO conjugate
• the "reaction buffer” as used herein is a standard buffer free of amine components, e.g., phosphate buffered saline (PBS).
• the reaction buffer has a salt, e.g., Na, concentration of about 0.ImM to about 10OmM, most preferably about ImM to about 5OmM, and even more preferably about 1OmM to about 2OmM.
• the polypeptide is mixed with the dry activated water-soluble polymer under stirring.
• the reaction buffer has a pH of about 6.5 to about 8.5 or about 6.6 to about 7.5. In preferred embodiments, the reaction buffer has a neutral pH of about 7.0.
• the molar ratio of protein (e.g., EPO) to activated water-soluble polymer in the reaction buffer is about 1 to about 3 to about 1 to about 60.
• the reaction buffer comprises a molar ratio of protein (e.g.) to activated water-soluble polymer of about 1 to about 6, to about 1 to about 60.
• the reaction buffer comprises a molar ratio of erythropoietin protein to activated water-soluble polymer of about 1 to about 7.
• the preferred reaction condition is a neutral reaction buffer of about pH 7.0 and comprising a molar ratio of water-soluble polymer to polypeptide of about 7 to about 1.
• the reaction buffer may further comprise an organic solvent.
• the preferred organic solvent is dimethyl sulfoxide ("DMSO").
• DMSO dimethyl sulfoxide
• the DMSO may be present in the reaction mixture in concentration of 5-80% and, preferably 10-40% (v/v).
• DMSO is widely used as a general solvent, but not for affecting pegylation reactions, in particular, for preferentially affecting the resulting sites of pegylation of said reaction.
• the reaction conditions described herein appear to specifically drive the covalent conjugation of the activated PEG toward particular lysine sites.
• addition of DMSO to the reaction buffer alters the sites of pegylation.
• the addition of DMSO to the reaction buffer as described herein drives the reaction toward the preferential pegylation of the protein at its amino- terminus, i.e., the amino-terminal ⁇ -amino group.
• the methods of the invention allow for selective modification of specific amino groups of the protein of interest, in particular, modification of the amino terminus of the protein.
• This selective modification of such proteins is beneficial in that it has been generally understood that associating water-soluble polymers, e.g., PEG, with proteins via amino-groups resulted in a loss of activity. It is believed that loss of activity commonly associated with pegylation was due to the random, lysine-targeted reactions of the prior art.
• Random modification of lysine residues may inadvertently alter protein function by substantially altering the tertiary structure or morphology of said protein.
• the reaction conditions disclosed herein appear to enable the selective modification of a protein at select residues or at its amino terminus, which is not generally believed to contribute to the activity of a protein.
• the methods of the invention are used to link one to two PEG molecules to specifically those EPO lysine residues whose linkage to PEG does not result in a loss of biological activity relative to native EPO but rather results in EPO conjugates that are surprisingly more clinically effective than native EPO.
• removing substantially all unlinked water-soluble polymer refers to generally known methods for carrying out such a separation, e.g., through dialysis. Generally, about 80% of unlinked water-soluble polymer is removed, preferably about 90% is removed, more preferably about 95% is removed and most preferably about 99% is removed.
• the invention provides protein conjugates, in particular, EPO conjugates, said conjugates comprising an erythropoietin glycoprotein having at least one water-soluble polymer attached thereto and having the in vivo biological activity of causing bone marrow cells to increase production of reticulocytes and red blood cells.
• the EPO glycoprotein is a human erythropoietin and/or analogs thereof having the sequence of human erythropoietin (e.g., SEQ ID NO:1 (FIG. 1); SEQ ID NO:2 (FIG. 2)) or an amino acid sequence substantially identical thereto.
• EPO or EPEG conjugates can be determined by methods described herein or standard assays known in the art.
• the biological activity of the purified EPO conjugates of the invention are such that administration of the inventive formulations (e.g., a plurality of EPO conjugates of the invention, or one or more components thereof, and a pharmaceutically acceptable carrier) to human patients results in bone marrow cells increasing production of reticulocytes and red blood cells relative to that of non-injected or control groups of subjects.
• the biological activity of the EPO conjugates, or fragments thereof, obtained and purified in accordance with the methods of the invention can be tested by methods, e.g., according to Annable, et al., Bull. WId. Hlth. Org. (1972) 47: 99-112 and Pharm. Europa Spec. Issue Erythropoietin BRP Bio 1997(2).
• Example 4 demonstrates that native EPO reaches its greatest serum concentration (i.e., achieves the highest blood borne activity of radiolabeled EPO conjugate) soon after it is injected and is then eliminated within 13 hours.
• a currently available glycosylated-EPO therapeutic, ARANESP® (darbopoietin alfa) (Amgen, Thousand Oaks, CA)
• ARANESP® (darbopoietin alfa) fails to reach significantly higher concentrations in the blood than native EPO.
• the concentration of blood-borne activity of EPEG conjugates of the invention are similar to both EPO and ARANESP® (darbopoietin alfa) over the initial about 12 hours; however, following about 12 hours, the concentration of activity of EPEG conjugates in the serum continued to increase and reached a maximal level about 50% higher than either EPO or ARANESP® (darbopoietin alfa) at 36 hours post injection. EPEG is cleared from the body about 26% to about 38% slower than ARANESP® (darbopoietin alfa).
• EPEG conjugates provide an increased total drug exposure, in terms of the area under the curve, than either the control EPO or ARANESP® (darbopoietin alfa).
• EPEG has an about 25% to an about 45% greater area under the curve (AUC) than ARANESP® (darbopoietin alfa); and 4 times greater AUC than native-EPO (see Example 4).
• AUC area under the curve
• EPEG may be administered less frequently than native EPO or other glycosylated-erythropoietin formulations, for example, ARANESP® (darbopoietin alfa), while still achieving higher levels of biological activity.
• the conjugates of this invention can be used in the same manner as unmodified polypeptides.
• the EPEG conjugates disclosed herein may be used in the same manner as native EPO.
• the conjugates of the invention have at least two unexpected, superior properties relative to prior pegylated polypeptides known in the art.
• the EPEG conjugates of the invention have unexpectedly high potency relative to control formulations and can be stored for prolonged periods of time in a protein free formulation (i.e., stored in a protein-free pharmaceutically acceptable carrier).
• the experimental results disclosed herein demonstrate that the conjugates of this invention have an increased circulating half-life and plasma residence time, decreased clearance rates and increased clinical activity in vivo relative to control formulations.
• the increased in vivo activity of the EPEG formulations of the invention relative to control formulations may be due to the increased plasma half -life.
• native EPO and its receptor are known to be processed and internalized by the cell. Once all EPO receptors are bound and internalized, EPO signaling has been maximized and cells are rendered insensitive to any excess native EPO still present in the body. As is demonstrated in the working examples herein, excess native EPO is then rapidly excreted by the body.
• the increased biological activity of plurality of EPO conjugates of the invention, or one or more components thereof may then be a function of the increased bioavailability and the increased half -life (i.e., increased circulation time) as compared to the receptor turnover time.
• an EPO-receptor Once an EPO-receptor is internalized, it requires a period of time for a new receptor to take its place.
• the circulating life of plurality of EPO conjugates of the invention, or one or more components thereof may be sufficiently long to bind to multiple generations of receptors prior to elimination.
• the EPO conjugates of the invention thereby increase in vivo activity, e.g., increase hematocrit induction, relative to that of native EPO or currently available glycosylated EPO formulations.
• the conjugates of this invention may be administered at reduced dosages and/or reduced schedules relative to those of unmodified EPO or currently available EPO-based formulations, e.g., once weekly instead of the three times weekly, respectively.
• the EPO conjugates of the invention may also be given to a subject in need thereof at least once daily, at least once every other day or at least once every third day. It is preferable, however, that an EPO conjugate formulation of the invention may be given to a patient in need thereof, at least once a week. More preferably, an EP) conjugate formulation of the invention may be given to a patient at least once every two weeks.
• the an EPO conjugate formulation of the invention may be given to a patient at least once a month or at least once every 6 weeks to two months.
• Decreased frequency of administration is expected to result in improved patient compliance leading to improved treatment outcomes, as well as improved patient quality of life.
• conjugates having the molecular weight and linker structure of the conjugates of the invention have an improved potency, stability, circulation AUC, circulating half-life, and cost of goods profile.
• the protein conjugates of the invention may be used as the native protein is used.
• EPEG formulations may be used as EPO is used, e.g., in treatment of anemia due to kidney diseases, cancer complications, chemotherapy, or HIV therapies.
• Other specific potential applications in accordance with this aspect of the invention include all diseases for which expansion of red blood cell would be beneficial to the patients (e.g., anemia).
• the exact amount of conjugate is a matter of preference subject to such factors as the exact type of condition being treated, the condition of the patient being treated, as well as other ingredients in the composition.
• the therapeutically effective amount is that amount of conjugate necessary for the in vivo biological activity of causing bone marrow cells to increase production of reticulocytes and red blood cells.
• the exact amount of conjugate is a matter of preference subject to such factors as the exact type of condition being treated, the condition of the patient being treated, as well as the other ingredients in the composition.
• the pharmaceutical compositions containing the conjugate may be formulated at a strength effective for administration by various means to a human patient experiencing blood disorders characterized by low or defective red blood cell production. Average therapeutically effective amounts of the conjugate may vary and in particular should be based upon the recommendations and prescription of a qualified physician.
• compositions of the invention may contain different amounts of EPEG, e.g. from about 10 to about 1000 ⁇ g/ml, preferably from about 50 ⁇ g/ml to about 400 ⁇ g/ml.
• compositions containing the conjugates of the invention may be formulated at a strength effective for administration by various means to a human patient experiencing blood disorders characterized by low or defective red blood cell production. Average therapeutically effective amounts of the conjugate may vary and should be based upon the recommendations and prescription of a qualified physician.
• compositions of the invention e.g. , the plurality of protein or erythropoietin glycoprotein conjugates, or one or more components thereof, prepared in accordance with this invention may be further rendered suitable for injection by mixture or combination with an additional pharmaceutically acceptable carrier or vehicle by methods known in the art.
• additional pharmaceutically acceptable carrier or vehicle e.g., saline, human serum album, human plasma proteins, etc.
• pharmaceutically acceptable carriers for formulating the products of the invention are saline, human serum album, human plasma proteins, etc.
• the invention also relates to pharmaceutical compositions comprising a conjugate as described above and a pharmaceutically acceptable excipient and/or carrier.
• Such pharmaceutically acceptable carriers may be aqueous or non-aqueous solutions, suspensions, and emulsions.
• non-aqueous solvents examples include propylene glycol, polyethylene glycol, vegetable oils such as olive oil, and injectable organic esters such as ethyl oleate.
• Aqueous carriers include water, alcoholic/aqueous solutions, emulsions or suspensions, including saline and buffered media.
• Parenteral vehicles include sodium chloride solution, Ringer's dextrose, dextrose and sodium chloride, lactated Ringer's or fixed oils.
• Intravenous vehicles include fluid and nutrient replenishers, electrolyte replenishers such as those based on Ringer's dextrose, and the like.
• Preservatives and other additives may also be present, such as, for example, antimicrobials, antioxidants, chelating agents, inert gases and the like.
• the protein conjugates prepared in accordance with this invention may be formulated in pharmaceutical compositions suitable for injection with a pharmaceutically acceptable carrier or vehicle by methods known in the art. See, e.g., WO97/09996, WO97/40850, WO98/58660, and WO99/07401 (each of which is hereby incorporated by reference in its entirety).
• the compounds of the present invention may be formulated, for example, in 10 mM sodium/potassium phosphate buffer at pH 7 containing a tonicity agent, e.g. 132 mM sodium chloride.
• the pharmaceutical composition may contain a preservative.
• the pharmaceutical compositions comprise an EPO conjugate as defined above, a multiply charged inorganic anion in a pharmaceutically acceptable buffer suitable to keep the solution pH in the range of from about 5.5 to about 7.0, and optionally one or more pharmaceutically acceptable carriers and/or excipients.
• the composition of the invention may comprise from about 10 ⁇ g to about 1000 ⁇ g erythropoietin conjugate per ml, 10-200 mmol/1 sulfate, about 10 to about 50 mmol/1 phosphate pH 6.0 to 6.5, optionally up to about 1 mM CaCl 2 , and optionally about 1-5% of a polyol.
• the EPEG conjugates of the invention have been shown to be resistant to degradation or loss of EPEG activity after at least 15 months of storage at low temperature (e.g., -20 0 C, 4 0 C) or at least 10 months of storage at elevated temperature (e.g., 25 0 C, 37 0 C) in protein-free solution and are expected to retain such stability for an extended period of time.
• the EPEG conjugates of the invention in such protein-free formulations may also be stable enough to ship and store under normal conditions, such as at room temperature.
• commercially available EPO e.g., EPREX® (epoetin alfa)
• HSA human serum albumin
• compositions containing human biological or serum derived ingredients such as HSA are subject to more stringent manufacturing requirements and regulatory compliance; and, as a result, are associated with substantially greater costs. It is possible, however, to formulate the inventive protein conjugates, e.g., EPO-conjugates, in a protein-free salt buffer without loss of the active pharmaceutical ingredient. As such, the ability to deliver a drug (e.g., EPEG) in a protein-free pharmaceutically acceptable carrier is of major economic advantage.
• a drug e.g., EPEG
• the pharmaceutical composition is made up of EPEG conjugate and a protein-free pharmaceutically acceptable carrier.
• the protein-free pharmaceutically acceptable carrier may include nonprotein excipients to further enhance the pharmacological properties of the EPEG conjugates. These include but are not limited to sugars such as mannitol, amino acids such as histidine, or a low level of conventional surfactants such as tween-80, etc.
• Mono-methoxylated PEG (molecular weight 12,000 KD) activated as a succinimidyl carbonate ester (SC-PEG- 12K) was used as the pegylating reagent.
• EPO produced in CHO cells was used as the polypeptide.
• the EPO-protein (50 mg) was prepared at a concentration of 0.61 mg/ml in a reaction buffer containing 0.15 mM NaCl, and 10 mM sodium phosphate, at pH 6.9. For certain experiments, the reaction buffer also contained 15% DMSO.
• the polypeptide solution was mixed with the dry PEG reagent while stirring to reach the final PEG/EPO molar ratio of 7: 1.
• the products of the reaction including DMSO, and un-reacted PEG molecules were separated by dialysis using a membrane having a molecular weight cut off of 25,000 KD.
• the final product contained a mixture of mono- pegylated EPO and di-pegylated EPO of approximate equal proportion, as determined by polyacrylamide gel electrophoresis (PAGE) (see, e.g., FIG. 3B).
• PAGE polyacrylamide gel electrophoresis
• SC-PEG 12 kD was used to pegylate EPO according to the protocol of
• Example 1 100 pico-moles of the protein was digested with TPCK- treated trypsin (Sigma, MO), at 4% of the weight of the substrate in 100 mM sodium phosphate pH8,4 at 37.C for 18 hours.
• the digest was analyzed on C18 reverse phase column (Apollo C-18, 5 u particle, 4.6X100 mm).
• the fragments were eluted using a linear gradient of 50 minutes from 100% of 0.125%TFA (trifluoroacetic acid) to 75% of acetonitrile/0.125% TFA. Eluted fragments were analyzed by UV wavelength at 230 nm.
• Example chromatograms are shown in FIGS. 3A and 3B for EPO and PEG-EPO, respectively. Peaks that were present in the EPO chromatogram but diminished or absent in the PEG-EPO elution profile indicate PEG modification and were characterized for their pegylation sites.
• G-CSF protein granulocyte-colony stimulating factor
• EPEG was prepared according to the methods of Example 1 , using reaction buffer containing DMSO.
• the product was filtered through a 0.2 ⁇ M membrane to reduce the bioburden, and was then diluted with PBS (phosphate buffered saline pH 6.9) to a final concentration of 50 ⁇ g/ml as determined by a BCA protein assay described infra.
• PBS phosphate buffered saline pH 6.9
• the product was sterile filtered into ImI vials for storage.
• the finished product was tested by the LAL test (Limulus Amebocyte Lysate pyrogen assay, Cambrex, MD) and had an endotoxin level of less than 0.1 EU per ml.
• vials were stored at 37 0 C, 25 0 C, 4 0 C or -20 0 C for subsequent stability and/or activity testing. Periodically, samples were tested for physical integrity by PAGE, for protein content by BCA protein assay, and for EPO activity by stimulation of the growth of the stem cells and hematocrit production. (See Example 3 for activity assays).
• Representative samples stored at 37 0 C, 25 0 C, 4 0 C or -2O 0 C were selected for a BCA protein assay (Pierce Chemical Co, MN) to quantify the total protein concentrations.
• 50 ul of sample or control was incubated in 175 ul of working reagent solution for 2 hours at 37 0 C and the absorbance at 650 nm determined.
• a 4-parameter regression was performed to determine the protein concentrations.
• a standard curve was generated with BSA (bovine serum albumin) and had a correlation coefficient of 0.999.
• the assay determined a protein concentrations of 50.5 ⁇ g/ml for the samples stored at 37 0 C, and 51.3 ⁇ g/ml for the samples stored at 25 0 C.
• the assay determined protein concentrations of 51.4 ⁇ g/ml for the sample stored at -20 0 C and 49.5 ⁇ g/ml for the sample stored at 4 0 C.
• the samples had concentrations of approximately 50 ⁇ g/ml determined by BCA. Therefore, there was no loss of protein over time.
• EPREX® epoetin alfa
• EPREX® cannot be used as standard in the BCA assay because it contains 0.2% HSA.
• EPEG was prepared according to the methods of Example 1 , using a reaction buffer without DMSO.
• the potency of EPEG was evaluated by the ability to stimulate stem cell differentiation into erythroid cells. Normal human bone marrow was used as the source of stem cells. The light density cells were obtained after Ficoll separation, (kit from Poietics Inc). The cells were resuspended in 10 ml of Iscove media containing 2% FBS and checked for viability with trypan blue.
• EPEG test samples at (50 ⁇ g/ml) and control samples were converted into units/ml for comparison assuming the standard 125,000 units/mg of EPO subsequent to the determination of protein concentration by BCA protein assay as described in Section 6.2.
• CFC colony forming cells
• CFU-E is an erythroid colony derived from a more mature progenitor and contains less than 200 erythroblasts.
• BFU-E is an erythroid colony derived from a primitive cell and contains greater than 200 erythroblasts.
• CFU-GM is the colony derived from a colony forming cell (CFC) capable of producing colonies with 40 or more granulocyte and/or macrophage cells.
• CFC colony forming cell
• the average coefficient of variation is 11% for 3 unit/ml, 25% for 1 unit/ml, 30% for 0.3 units/ml, and 50% for 0.1 unit/ml.
• the p-values for the confidence levels were P ⁇ 0.01. After five months of storage in a protein free media, EPEG samples maintained full activity. Assay results were subjected to statistical analysis. Standard t-tests were performed to assess the difference in the number of colonies generated between cultures tested with EPO and the PEG-EPO at equivalent concentrations. A p value of less than 0.01 is deemed significant. The observed data indicate the result is within this significance level. Similar results were obtained using EPEG prepared in reaction buffer containing DMSO.
• EPO-PEG201 and EPO-PEG202 Two different lots of EPEG (EPO-PEG201 and EPO-PEG202) were prepared according to the methodology of Example 1 using reaction buffer without DMSO (i.e., native EPO was modified by SC-PEG- 12K at the lysine sites) and the resulting protein concentrations of the samples determined by BCA assay as described in section 6.3. These EPEG compounds were used to compare the pharmacokinetic profile to the native, unmodified, naturally functional EPO and the FDA-approved EPO-hyperglycosylated (ARANESP® (darbopoietin alfa), from Amgen, Inc., Thousand Oaks, CA).
• ARANESP® FDA-approved EPO-hyperglycosylated
• ARANESP® (darbopoietin alfa) was used as a benchmark because it is an FDA-approved product and has a prolonged half life due to hyperglycosylation of the protein.
• IPEG-EPO to 2PEG-EPO ratios were 54:46 in EPO-PEG201; and 45:55 in EPO-PEG202.
• protein solutions at the dosage of 4 Ci/kg body weight were injected subcutaneously into male Sprague-Dawley rats. The rats were divided into 5 subgroups with 4 animals each to avoid more than 3 blood samplings for each animal. Blood samples were taken at different time points after injection (0, 0.5, 1, 2, 4, 8, 12, 16, 24, 36, 48, 72, 96 and 120 hours). The amount of radio-labeled protein in the blood sample was determined using a scintillation counter and the generated data were statistically evaluated. Results are shown in FIG. 7.
• EPO-PEG201 and EPO-PEG202 have similar pharmacokinetic profiles. Surprisingly, the Inventors discovered that both have a higher and broader PK profile than either ARANESP® (darbopoietin alfa) or native EPO. Table 2 shows the results of the analysis of the PK parameters using a one-compartment model and dosage accumulation.
• EPEG was cleared from the body about 26% to about 38% slower than ARANESP® (darbopoietin alfa). This results in a superior total exposure, in terms of the area under the curve, than either the control EPO or ARANESP® (darbopoietin alfa). In fact, EPEG has an about 25% to an about 45% greater area under the curve (AUC) than ARANESP® (darbopoietin alfa); and 4 times greater than native-EPO.
• AUC area under the curve
• Example 1 using reaction buffer without DMSO and using different varieties of activated PEG.
• the amount of activated PEG used in the pegylation reaction was adjusted such that the final product contained approximately equal amounts of IPEG-EPO and 2PEG-EPO.
• IPEG-EPO and 2PEG-EPO were purified using DEAE column chromatography. The column was equilibrated with a buffer containing 75 mM NaCL, 5 mM sodium phosphate at pH 6.75. After reaction, the sample was dialyzed against the same buffer, and then loaded onto the column for purification. Small amounts of highly modified PEG-EPO did not bind to the column and eluted in the wash.
• the samples were eluted with a gradient to 97.5 mM NaCL, 5 mM sodium phosphate pH 6.75. Any native EPO was eluted with 150 mM NaCL in sodium phosphate buffer pH 6.75. Eluted fractions were evaluated by polyacrylamide gel electrophoresis. The fractions were separated into 3 groups: IPEG-EPO, 2-PEG-PEG and an equal mixture of the two.
• Y501P EPO modified by branched chain NHS-PEG (20 kD) with IPEG-EPO
• Y502P EPO modified with branched chain NHS-PEG (20 kD) with 2PEG-EPO
• Y5012 EPO modified with branched chain NHS-PEG (20 kD) with equal amount of IPEG-EPO and 2PEG-EPO
• L33 EPO modified with linear chain SC-PEG (12 kD) with equal amount of IPEG-EPO and 2PEG-EPO
• X6012 EPO modified with branched NHS-PEG (40 kD) with equal amount of IPEG-EPO and 2PEG-EPO. Protein concentrations of the final samples were determined as described in section 6.3 .
• EPEG samples produced as outlined in Example 6 were administered to rats to compare and evaluate activity : Y501P (IPEG-EPO), Y502P (2PEG-EPO) and Y5012 (mix IPEG-EPO and 2PEG-EPO).
• Sprague-Dawley rats (specific pathogen free, 5 weeks old, male) were housed in filter-top cages in an air-conditioned animal facility. Water was provided ad libitum. Rats are adapted for one week after arrival before the study. EPEG samples were diluted with PBS before injection. The rats (each approximately 250 g) were injected subcutaneously with 5 ⁇ g total protein in 1 ml of buffer (PBS) or 1 ml PBS (control) and hematocrit was monitored over 25 days. Hematocrit was determined by drawing blood from the tail vein into a heparinized capillary tube (Marienfld, Germany).
• EPEG variants produced as described in Example 6 were further tested in the mouse model of hematocrit induction outlined in Example 7.
• the EPEG formulations selected for this assay each comprised approximately equal amounts of IPEG-EPO and 2PEG-EPO: L33, Y5012, and X6012 (see Example 5). Their in vivo activity in terms of increased hematocrit was compared to that of PBS and native EPO. As described supra, each animal received approximately 5 ⁇ g of active agent, i.e., total protein As shown in FIG. 9, L33 and Y5012 have similar effect, with Y5012 slightly more active. Higher molecular weights of PEG did not further increase this activity.
• Example 9 PEG-EPO is more potent than native EPO
• L33 EPEG i. e. , linear SC-PEG- 12K as activated PEG
• the EPEG formulation was evaluated for in vivo activity according to the rat model according to Examples 7 and 8. Hematocrit levels were evaluated at 0, 2, 5, 7, 10 and 14 days.
• the native EPO for control was a recombinant human EPO (rhu-EPO) produced in a baculoviral expression system (as commonly known in the art, Rhu-EPO has the same amino acid sequences as the original human EPO, but the glycosylation pattern is different).
• rhu-EPO recombinant human EPO
• Rhu-EPO has the same amino acid sequences as the original human EPO, but the glycosylation pattern is different.
• EPEG or rhu EPO was administered to the rats as a single injection at a dosage of 2.5 or 5 ⁇ g per animal (each approximately 250 grams).
• EPEG at 2.5 ⁇ g protein per rat exhibited the same effect as a 5 ⁇ g dosage of the control, rhu-EPO, suggesting that the EPEG of the invention is twice as potent as the control.
• EPEG With a 5 ⁇ g dosage, EPEG induced a hematocrit level of about 80%, almost twice that inducible by the un-modified, i.e., non-pegylated, EPO.
• the control, rhu-EPO at 5 ⁇ g dose a exerted similar level hematocrit induction as the 2.5 ⁇ g dose. The result suggests that the control EPO had already reached a plateau in hematocrit induction at the tested dosages.

Landscapes

• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Medicinal Chemistry (AREA)
• General Health & Medical Sciences (AREA)
• Gastroenterology & Hepatology (AREA)
• Zoology (AREA)
• Proteomics, Peptides & Aminoacids (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Pharmacology & Pharmacy (AREA)
• Bioinformatics & Cheminformatics (AREA)
• Animal Behavior & Ethology (AREA)
• Engineering & Computer Science (AREA)
• Biophysics (AREA)
• Genetics & Genomics (AREA)
• Toxicology (AREA)
• Molecular Biology (AREA)
• Biochemistry (AREA)
• Epidemiology (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Hematology (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Diabetes (AREA)
• Immunology (AREA)
• General Chemical & Material Sciences (AREA)
• Endocrinology (AREA)
• Medicines That Contain Protein Lipid Enzymes And Other Medicines (AREA)
• Medicinal Preparation (AREA)
• Peptides Or Proteins (AREA)

Priority Applications (12)

Applications Claiming Priority (2)

Publications (1)

Family

ID=39033318

Family Applications (1)

Country Status (14)

Cited By (3)

Families Citing this family (4)

Citations (31)

Family Cites Families (29)

• 2007
  • 2007-07-16 CA CA2659990A patent/CA2659990C/en not_active Expired - Fee Related
  • 2007-07-16 CN CNA200780037291XA patent/CN101534847A/zh active Pending
  • 2007-07-16 KR KR1020097004580A patent/KR20090046923A/ko not_active IP Right Cessation
  • 2007-07-16 WO PCT/US2007/073629 patent/WO2008019214A1/en active Application Filing
  • 2007-07-16 US US12/376,333 patent/US8765924B2/en not_active Expired - Fee Related
  • 2007-07-16 JP JP2009522923A patent/JP5723528B2/ja active Active
  • 2007-07-16 KR KR1020127016845A patent/KR101304081B1/ko active IP Right Grant
  • 2007-07-16 SI SI200731546T patent/SI2054074T1/sl unknown
  • 2007-07-16 PL PL07812992T patent/PL2054074T3/pl unknown
  • 2007-07-16 ES ES07812992.1T patent/ES2529234T3/es active Active
  • 2007-07-16 CN CN201610113341.9A patent/CN105820231A/zh active Pending
  • 2007-07-16 EP EP07812992.1A patent/EP2054074B8/en active Active
  • 2007-07-16 DK DK07812992.1T patent/DK2054074T3/da active
  • 2007-07-16 PT PT78129921T patent/PT2054074E/pt unknown
• 2009
  • 2009-02-03 IL IL196866A patent/IL196866A/en active IP Right Grant
  • 2009-10-26 HK HK09109876.1A patent/HK1131542A1/xx not_active IP Right Cessation
• 2012
  • 2012-12-06 JP JP2012267283A patent/JP5802644B2/ja not_active Expired - Fee Related
• 2014
  • 2014-06-02 IL IL232923A patent/IL232923A/en active IP Right Grant
• 2015
  • 2015-06-24 JP JP2015126468A patent/JP5961730B2/ja not_active Expired - Fee Related

Patent Citations (33)

Non-Patent Citations (26)

Also Published As

Similar Documents

Legal Events